The present invention relates to the construction of printed circuit board STORAGE CABINETS and the like and in particular to cabinets having interchangeable retaining plates on which spare or currently unused printed circuit boards are retained, whereby the storage cabinet is adjustable and can be made to easily accommodate a variety of printed circuit board sizes.
Printed circuit board storage cabinets have been disclosed in my prior patents U.S. Pat. Nos. 4,184,599, Jan. 22, 1980 and 4,277,120, July 7, 1981. These storage cabinets are particularly advantageous for the storage of a large supply of spare, properly functional printed circuit boards, at locations where such boards are in constant use, such as telephone switching stations, computer terminal locations and the like. Such cabinets are also used to maintain a supply of printed circuit boards for performing alternate functions, different from those normally performed by the operating equipment.
The retaining and storage cabinets comprise a generally parallelepiped frame housing having top and bottom supporting members connected by a pair of height adjustable side walls. Attached to each of the top and bottom supporting members are several printed circuit board retainers each comprising a substantially flat planar plate having a plurality of parallel grooves of predetermined width. The printed board circuit retaining plates are arranged so as to be in paired opposition on the top and bottom supporting members allowing the printed circuit board to be slidably inserted in opposing grooves and be retained therein perpendicular to the top and bottom supporting members.
Each of the printed circuit board retaining plates is provided with means for interlocking with the adjacently disposed plates, so as to form a substantially continuous and unbroken planar surface of a plurality of said plates on the top and bottom supporting members respectively, as if the same were unitarily formed. In addition to the interlocking means along the edges of each plate, each of the plates are provided with means for detachably securing the plate to the top and bottom member, whereby the plates are rigidly held. Such detachable engagement means generally comprises a plug which is received in a preformed hole or aperture made in the top or bottom supporting surface. The arrangement as shown in the aforementioned patents secures and locks the retaining plates into fixed position more or less permanently.
While it is possible to ensure that printed circuit boards are formed in generally overall length and width dimensions similar to each other, it is more difficult to insure that their base thickness remains uniform, or that the overall thickness remains uniform, since the components mounted on the circuit boards may themselves vary in thickness. Therefore, it is advantageous to provide a printed circuit board storage cabinet which is capable of storing circuit boards of different thickness.
Accordingly, it has become the practice to provide the aforementioned storage cabinet with opposed pairs of printed circuit retaining plates, which have grooves of a different width than those of other paired retaining plates. This has had only an ameliorating effect in the solution of the problem for adjustability, since it is often impossible to determine beforehand the nature of the printed circuits which are required to be stored, so that once the storage cabinet has been assembled and put in place, it is difficult to make any adjustment for differences in thicknesses of boards to be stored.
The interlocking edge means, and the means for detachably engaging the plates to the top and bottom supporting surfaces respectively, do not allow for the swift and easy removal of any of the retaining plates and their subsequent replacement with other retaining plates having different width grooves. Further, banana plugs as used in U.S. Pat. No. 4,277,120 sometimes tend to break when withdrawn from their holes, and thus cease to function to effectively hold the plates in place when the plates are reused.
It is an object of the present invention to provide a printed circuit board storage cabinet, overcoming the disadvantages of the prior devices.
It is a further object of the present invention to provide a printed circuit board storage cabinet having retaining plates which are easily insertable and removable from the frame housing enabling plates having different configurations to be easily interchangeable with each other.
In particular, it is an object of the present invention to provide a printed circuit board storage cabinet which includes provision for facilitating the interchange of the retaining plates to accommodate printed circuit boards of differing base thickness, overall thickness, as well as overall width.
Further objects, features and advantages of the present invention will be more fully appreciated by reference to the following detailed disclosure of the present invention.